Biodegradação do cloranfenicol por fungos endofíticos isolados de Bertholletia excelsa (Castanha-do-Brasil)

Abstract

Introduction: Antibiotics are a group of micropollutants at great risk to ecosystems and contribute to the development of resistance in bacterial strains when discarded incorrectly or by indiscriminate use Chloramphenicol, the compound addressed in this study, resists conventional degradation procedures in the treatment of residual water. Thus, the biodegradation process employing specific and efficient microrganisms, including filamentous fungi, is an ecologically viable and low cost option that has already been used successfully for the biodegradation of other chemical agents. Objective: The objective of this study was to evaluate the biodegradability of the decoranphenicol molecule by five endophytic fungi isolated from Bertholletia excelsa collected in the Brazilian Amazon. Methodology: For this, the strains of BIORG 4, BIORG 5, BIORG 6, BIORG 7 and BIORG 9 were screened in solid / liquid medium and the experimental design was performed to optimize the culture conditions by varying the pH of the medium, the chloramphenicol concentration and the reaction time. Analysis by High Performance Liquid Chromatography (HPLC-UV) was performed to quantify the biodegradation content and Gas Chromatography coupled to Mass Spectrometry (GC-MS) was used for the detection and identification of metabolites. In addition, an environmental toxicological assessment was performed using the Chlorella vulgaris algae. Results and Discussion: Results of fungal cultures on solid medium showed that chloramphenicol significantly affected the growth of fungal strains. In addition, the initial scarification of biodegradation at 3, 6 and 9 days showed that all strains succeeded in increasing the degradation of this antibiotic; Trichoderma sp. (5, 7 and 9), period (24, 48 and 72 hours), which was submitted to an experimental design (Box-behnken) ) and chloramphenicol concentration (50, 100 and 150 mg.L-1), reaching a biodegradation percentage of about 30%. The metabolite 4-nitrobenzaldehyde was identified and showed toxicity to these microorganisms, a metabolite that may be related to the diseases caused in different organisms. Conclusions: Endophytic fungi have been able to accelerate the biodegradation of chloramphenicol and can be better studied in waste treatment facilities. In addition, it was the first biodegradation study with isolated fungi of the Amazon